Debates about the meaning and requirements for child assent to research participation permeate the bioethics, medical, and psychology literatures, but empirical research in this area is in its infancy. The assent process is important for conforming to research regulations but can also be used to enhance children's sense of self- efficacy in health care settings. Optimizing children's roles in research decision making is critical, especially during pre-adolescence and adolescence, when children begin to strive for and acquire more decision making independence. Prior research on child assent has been based on a model that focuses on cognitive capabilities; this research examines children's understanding of the elements of research and the factors that influence their understanding. A second model of child assent focuses on the relational context of children's decision making. This model recognizes that decision making typically occurs in a family context and attends to the role of collaborative decision making in normative development. The relational model focuses not on who makes the decision, but on how parents and children talk about it. It reflects the view that children can be involved in decisions in various ways and that parents play an important role as sources of support and advice across the child's development. The primary objective of this research is to examine the benefits of children's involvement in decisions about clinical trial enrollment and whether these benefits vary based on child demographic and psychosocial characteristics. In other words, do some children benefit more from involvement than others? For the purpose of this research, the potential benefits of assent include children's perceptions of the fairness of the decision making process and their sense of self-efficacy. The assumption of the proposed research is that how adults and children interact about the research decision is more relevant for children's self-efficacy than who ultimately makes the decision. This innovative study will assess families within 10 days of having made an actual decision about clinical trial enrollment for the treatment of a chronic condition in the child. The research team will test the relationship between child involvement in the research decision and perception of fairness and self-efficacy (Aim 1), determine if the relationship between child involvement and the benefits of child assent depends on child demographic and psychosocial characteristics, such as age and perceived stress (Aim 2), and test the relationship between child involvement in the research decision and characteristics of the research, including perceived risks and benefits and research personnel behaviors (Aim 3). This research will provide data about children's actual involvement in research decisions and the factors that make their involvement more or less beneficial. Data from this project has implications for ethical questions related to child assent and will lead to the development of interventions and guidelines to enhance child involvement in research decision making.